The present invention relates to the field of dental cleansing equipment and, more particularly, to a system for delivering an abrasive laden stream for use in cleaning teeth.
The surfaces of teeth are subject to deposits of foreign materials, broadly classified as stain and calculus. The source of such foreign material ranges from natural fluids, such as blood and saliva, to food, drink and tobacco smoke. Regardless of the source, however, stain and calculus usually result in discoloration of the tooth surface.
It is well-known that stain and calculus may be removed from a tooth by an abrasive action. Prior art methods for providing such action include the use of abrasive pastes containing pumice or silex, as well as the use of air-abrasive equipment. In the latter case, a stream of abrasive laden gas is directed against the tooth which is to be cleaned and the repetitive action of abrasive particles striking the tooth surface produces the desired cleaning.
Air abrasive equipment exmplifying such prior art devices are described and claimed in U.S. Pat. Nos. 3,882,638 and 3,972,123 to Robert B. Black. Another system is the subject of U.S. Pat. No. 4,174,571 to Ben J. Gallant. The apparatus and methods disclosed in these patents provide for the delivery of an abrasive laden gaseous stream surrounded by a plurality of discrete streams of liquid. The liquid streams are employed to enclose the abrasive material during delivery and prevent its premature disperal before the surface of the tooth is encountered.
In each of these prior art devices, the abrasive material is kept in containers in a supply cabinet and delivered to the tooth via a handpiece connected to said cabinet. The cabinet also houses the control mechanisms, e.g. valves, pumps, etc., which create the abrasive laden stream delivered to the handpiece. Since supplies of pressurized air and liquid are already available in many other pieces of dental equipment, the need for an additional cabinet to house the abrasive and control circuitry is an undesirable use of critical office and operating space.
Furthermore, in such systems the abrasive must be removed and all abrasive-carrying lines cleaned each night so as to prevent clogging of the system during subsequent use. This is a time-consuming procedure and can be very dirty. Such problems detract from the attractiveness of purchasing and using air-abrasive equipment.